Dilatometer



June 11, 1929. l s. P. RocKwl-:LL 1,716,796

DILATOMETER Filed June 29, 1928 Patented June 11, 1929.

nieren ST'ES STANLEY P. ROCKVJELL, F WEST HARTFORD, CONNECTICUT.

DILATOMETER.

Application filed June 29,

My invention relates to the class of devices more particularly employed for determining certain phenomena in metals when subjected to variations in temperature, and an object of my invention, among others, is the production of a device by means of which extreme accuracy may be Sie/(nuked in determining certain results.

(')ne form of device embodjf'ing my invention and in the construction and use of which the objects hereiiii out, as well others, may beattained, i. ted in. the accompanying drawings, in whichll`igure 1 is a view in elevation of an apparatus embodying my invention with the fun nace broken away' to show the interior thereof.

Figure 2 is a similar view, but looking` at the apparatus from a point located at right angles to the point of view of Figure 1, and with. parts beyond omitted.

Figure 2-3 is a top view of the device.

Figure 4 is a view in section of a portion of tho device on a plane denoted by the dotted line -lmt of Figure 1.

1n the accompanying drawings the numeral 5 denotes as a whole an instrument by means of which certain results may be ob-n tained in the heat treatment of metals, such instrument being of old an d well lrn own construction and forming, except in connection with parts to be hereinafter described, no part of my present invention and being illustrated herein. .merely for a disclosure of such invention. Said instrument is shown as supported upon a. table 6 and comprises a lever 7 that, when moved, actuates an indicator 8 and a recording mechanism 9, the latter including a cylinder 10 on which a sheet of paper is placed to receive the record.

My improved device comprises a furnace 11 which may be, as to general characteristics, of any well known form and construei tion, that herein shown being of the electric type and which is employed for the purpose of heating pieces of metal to determine certain characteristics thereof.

1t is of value in many instances to determine to as exact a degree as may be possible the amount of contraction and expansion of metals under heating and cooling conditions, but with apparatus heretofore used extreme accuracy has been impossible by reason of the influence of outside agencies upon the metal. For instance, with a recording instrument, as hereinV shown and heretoforeV 1928. serial No. 289,188.

used, a piece of metal 12 has been placed in the furnace 11,. resting upon a support placed on the bottom to the furnace, and a connection has been. made between said piece of metal and the lover 7 of the recording instrument. The amount of expansion and contraction of the piece of metal, however, iny this operation, has been influenced to a great extent by the -furnace as well as the supports thereof, and also by the support for the metallic article within the furnace, the expansion and contraction of all of which .must of necessity be considered and which cannot accurately be separated from the expansien and contraction of the metal piece itself owing to the great degree of influence cxterted by such members. 1n order to reduce these outside influences to a minimum 1 provide a base 13 to support the piece of metal 12, this base resting as upon a base plate 1&1 of the instrument as a whole. A rod 15 is secured to and rises from the base 13 and forms the immediate support upon which the V'piece 12 rests. This rod is con structed of quartz or other suitable mate` rial that is influenced as to expansion and contraction to a minimum degree by the furnace; Resting upon the piece 12 of metal is anotherA rod 1G that is in contact with the piece of metal which. is also composed of quartz or other similar material not readily influenced by the heat. Upon the rod 16 is a head 17 secured to the lower endof a rod 18, the upper end. of which is in contact with the llever 7, said rod 18 being loosely attached to the frame of the instrument 5 as by means of screws 19 projecting through holes in the frame considerably larger in diameter than the screws so-that in the operation of the instrument upon any piece of metal within its range the screws 19 will not touch the edges of the holes through which they project. Vith different sizes of pieces 12 being operated upon an adjusting screw 2O is employed to adjust the position of the frame of the instrument to set the pointer of the indicator 8 at zero.

1n order that the heat of the furnace shall alfect the rods 15 and 1G to a minimum degree the furnace is provided with openings A21 at the top and bottom considerably larger in diameter than that of said rods so that there is quite a little space between the edges of the openings and the outer surface of the rods.

In the use of the apparatus thus described it Will be noted that practically the entire expansion or contraction of the metal piece i2 w'll be indicated by the recording and indicatingY instrument, the influence of the heat o'i" the furnace upon the supports 'for the metal piece being,` practically negligible, and even this being reduced by employing' a material which is little influenced by the heat ot the furnace. It it shall be desired to obtain more accurate data than are indicated by the instrument, the quartz rods may be placed in contact, the furnace heated to the required degree and the reading ot the recording instruments taken. Thorn, after a piece olf metal has been heated to the required degree and a reading;n taken to denote the amount olf expansion, the amount ot e1;- pansion before taken lwhen the quartz rods onlyY were in the furnace may be deducted and this will enable an extremely close determination oitl the expansion ot contraction to be had. ln tact, in most instances it will not be necessary to take into consideration the difference in expansion last described.

n accordance with the provisions ot the patent statutes have described the principles oi? operation of my invention, together with the apparatus which l now consider to represent the best embodiment thereof; but l desire to have it understood that the device shown is only illustrative and that the invention may be carried out by other means ind applied to uses other than those above set out.

claiml. A d'ilatonieter includinga heat-ine; turnace, a support projecting' from outside otr the tnrnace to a point therein Without touching' the furnace and adapted to receive ivithin the furnace a piece to be tested, an inilicatine' instrument, a connectingelement adapteil to rest upon said piece and to extend i'o a point outside the furnace Without touching,` the same, and ay connection between said connect-ing element and said indicating` instrument for actuation ot the latter.

2. A dilatometer including` a heating,` furnace, having` openings therein, a support s ialler than said openings and projecting from outside the furnace to a point therein and adapted to receive a piece to be tested, an indicating device, a connecting' element smaller than one of said holes and projecting therethrough to a point outside ot the furnace, said element being adapted to rest upon said piece, and a connection between maid element and said indicating piece for actuation of the latter.

3. A dilatometer including a heating turnace, a support having' minimum heat at- 'fecting (pialitiesI pr ijecting trom outside the furnace to a. point therein without touchin e; the 'furnace and adapted to receive Within the furnace a piece to be tested, an indicating instrument, a connecting` element composed ot material adapted to be afl.:- ceted by heat to a minimum extent and adapted to rest upon said piece and to extend to a point outside the furnace Without 'fontaine' the same, and a connection between said connecting,` element and said indicating' instrument 'For actuation otl the latter.

1l. A dilatometer including; a heating,` furnace having` a hole at each end thereof, a supportr composed ot quartz projecting from outside the furnace through one of said holes, said support beine,` smaller in diameter than said hole. and being;` adapted to receive a piece to be tested, an indicating` instrument, a connecting' element composed of quartz adapted to rest upon said piece to pass through the other hole in said furnace and smaller in diameter than said hole, and a connect-ion between said conneci'ine' element and said instrument for actuation ot the latter.

STANLEY P. ROCKVELL. 

